Usual comforters comprise a plug maintaining the teat rubber in the centre of the safety shield. The baby may place such a comforter so that the hard safety shield preventing the baby from swallowing the comforter abuts the rim of the lower teeth whereas the upper front teeth abut the portion of the plug extending a short distance downwards through the hole of the rubber teat. As a result the front upper teeth are subjected to a heavy pressure from below. However, the baby may bite so hard in the rubber plug end that the teeth bite through the rubber and finally bite said rubber in two so thaat the baby may either swallow said rubber or get it into the trachea. Furthermore, these known comforters have the drawback that it is impossible to keep the connection between the rubber and the plastic placed immediately in front of the mouth bacteria-free. The baby may also be sucking these known comforters so that a vacuum arises in the oral cavity involving a deformation of the palate so that the palate becomes high and narrow. This drawback may influence the rudiment for the permanent teeth present above the milk teeth in the jawbone so that the permanent teeth become malpositioned or pointed outwards. Moreover, the baby may by means of the known comforters form a tight loop beneath the front teeth by pushing the teat rubber backwards against the palate with the tongue. Although the outer shape of these comforters may resemble the mamma, they have all the above drawbacks.
British patent specification No. 27,198 discloses a comforter comprising a safety shield and a teat rubber, the projecting collar of which surrounds the plane safety shield and is tightened thereabout, said collar comprising a flange curved backwards. This comforter comprises a plane, rigid surface facing the mouth of the baby and may imply excoriation about the mouth. This surface comprises no movability. The teat rubber is the natural rubber usually used for all comforters today, and then influenced by the saliva this rubber dissolves and swells in such a manner tht the surface after use for a short time is porous, which provides favourable conditions for bacteria. By storage for a long time the rubber oxidizes and turns hard, which implies tht a baby may easily bite the teat body into two and either swallow said body or get it into the trachea. As a consequence of the crumbling of the teat rubber, requirements exist for the lifetime for the rubber, before the expiration of which the comforters must be returned to the producer.